Process for treating cellulosic fibers with alkali



Patented Sept. 116, I93@ UN HT GIGVANNI TAG-LIANI, F BASEL, SWITZERLAND, ASSIGNOR TO THE FIRM: CHEMICAL WORKS FORMERLY SANDOZ, OF BASEL, SWITZERLAND PROCESS FOR TREATING CELLULOSIC FIBERS WITH ALKALI Ito Drawing. Application filed September 7, 1927, Serial No. 218,109, and in Germany October :39, 1926.

Various attempts have been made to improve the alkaline treatment of natural and artificial cellulosic fibers, such as is realized for instance in the mercerizing process, by the use of convenient admixtures. Soaps, sulphoricinoleic acids, alcohols and other substances have been proposed for this purpose. These admixtures have only little ef feet, so that large quantities are necessary to obtain a satisfactory result, which renders the process expensive. For instance, 20- 30% of alcohol, calculated on the mercerizing lye, is necessary to merceriz e satisfac torily a raw and sized cotton fabric Without a previous bowking.

, It has unexpectedly been found that this process can be considerably improved, if small quantities of a suitable mixtureof phenolic substances and hydrogenated aromatic substances are added to the mercerizing lye, the action of the alkali is then quicker and more uniform. By the aid ofthese admixtures it is possible ,to mercerize raw and sized cotton fabrics without previous bowking. These fabrics would otherwise not produce uniform effects without a previous bowkin Theaddition of henol alone to mercerizing lyes is already nown. According to the U. S. specification 1,343,139 textile fabrics o composed of mercerizable cellulosic fibers intermixed with artificial silk-filaments of viscose are mercerized with a lye containing 5% of phenol. :This addition has the only oblject to allow the performance of the mercerization of the cellulosic fiber without injury to the viscose silk, because, as is proved by many tests, phenol as well as its homologues do not effect at all the mercerizing operation of ordinary cotton. The hydrogenated aro- 40 matic compounds being entlrely insoluble in the concentrated alkaline lyes used for mercerization would not by themselves improve I the process;

, with phenols as set forth above they act as very good wetting-out agents and greatly improve the wetting-out ca acity of the alkaline lyes. This remarkably good action is based on the fact that the alkali phenolates formed in the mercerizing lye act as solvent and dispersing agent for the hydrogenated But if they are used jointly aromatic compounds so as to allow to practically utilize their excellent wetting-out action.

The following hydrogenated aromatic substances come into consideration for the present process: The products of hydrogenation of naphthalene, naphthols and phenols, as for instance tetrahydroand decahydronaphthalene, hydrogenated naphthols, cyclohexanol, methylcylohexanols and mixtures of these substances. As phenolic substances, ordinary phenol, then especially the cresols and mixtures of them, further the higher phenol homologues may be used.

Mixtures of 52-12% of hydrogenated aromaticsubstances with 98-88% of phenols are most suitable for carrying out the new process, but this does not mean that mixtures of other proportions would be useless.

The effect of these admixtures is obtained even with small quantities (12% of the weight of the mercerizing lye). It consists in an increase of the wetting properties of the cellulosic fibers to an unexpected degree. This strong increase is the more unex- 'pected as neither the phenols nor the hydrogenated' aromatic substances by them selves cause appreciable increase of the wetting'properties; only mixtures of such substances have this effect. The increase of the wetting properties of the fibers results not only in a quicker action of the alkali, but also in a more uniform effect.

Emample 1;

A raw and unbowked cotton fabric is mercerized with a caustic soda lye'of 34 B. to which 1 of a mixture of 91% of a cresol mixture 'and 9% of a methylcycloincreased elasticity together with a deeper mercerization than that mercerized according to the old mercerizing process. Further the operation is carried out in a shorter time than is the ca e Without the mixt re.

Emample 2 fil of a mixture of 95% of cresols and 5% of tetrahydronaphthalene is added a to a mercerizing lye of 36 B. the same efl'ect 5 as described in Example 1 is observed.

Example 3 A viscose fabric containing fibers which have been produced in different manufacturing operations is passed through a mercerizing lye of 20 B. to which 1 (calculated on the weight of the lye) of a mixture oiE 90% of a cresolimixtu're and 10% of methylcyclohexanolmixture are added. The fabric is then squeezed out. The fabric thus treated vcan be dyed in more even shades than without this treatment. 7 What I claim is:

1. An improved process for thetreatment of natural and artificial cellulose fibers with alkali, consisting in adding a mixture of a phenol and hydrogenated aromatic substances to the alkaline medium.

2. An improved process for the treatment of natural and artificial cellulosic fibers with alkali, consisting in adding. a mixture of a 1 cresol mixture and a methylcyclohexanol mixture to the alkaline medium.

3. An improvedprocess for the treatment of natural and artificial cellulosic fibers with alkali, consisting in adding a mixture of 212% of hydrogenated aromatic substances and of 98-88% of phenolic substances to the\ 35 alkaline lye, said mixture being added in quantities of 12% reckoned on .the weight of the lye.

In witness whereof Ihave hereunto signed my name this 25th day of August 1927.

. GIOVANNI TAGLIANI. 

